Gas engine



April 1953 s. D. ,KLINGER 2,635,589

GAS ENGINE Filed Jan. 11. 1947 6 Sheets-Sheet 1 52 7 llvvL-fivrok STUARTD. KLINGER Hr TORNEY April 21, 1953 s. D. KLINGER GAS ENGINE 6Sheets-Sheet 2 Filed Jan. 11, 1947 R "L m w M fi n M m M A U T f w 5 a P1953 s. D. KLINGER 2,635,589

GAS ENGINE Filed Jan. 11, 1947 6 Sheets-Sheet 3 /N|/E/V7OR STUART D.KLINGER fir 7-0 aver April 1953 s. D. KLINGER 2,635,589

GAS ENGINE Filed Jan. 11, 194? s She ets-Sheet 5 /m /7'a, STUART D.KLINGER Ap 1953 s. D. KLINGER 2,635,589

GAS ENGINE Filed Jan. 11, 1947 6 Sheets-Sheet 6 flvrezvraae STUART D.KLINGER No. 579,374, now, Patent No. 2,562,511.

Patented Apr. 21, 1953 UNITED STATE s PATENT OFFICE GAS ENGINE Stuart D.Klinger, Beloit, Wis., assignor to Fairbanks, Morse & 00., Chicago,Ill.,a corporation of Illinois Application January 11, 1947, Serial No.721,593

of. the present type, that is a two-cycle diesel engine, have beendisclosed in great detail in a prior application for patent; entitled.Gas Engine; filedin the name of Clarence H. Schowalter on February 23,1945, and bearing Serial As was there pointed out, the improvementsprovide :a high compression gas engine wherein the compression pressureattained is of the order of that normally occurrin in a diesel engine ofcomparable size, in which is embodied a gaseous fuel combustion spaceauxiliary to the cylinder combustion space and having a restrictedcommunication with the latter. In operation,

gaseous fuel is supplied under a pressure which is very materially lessthan the maximum compression pressure attained in the engine and .isintroduced to the auxiliary combustion space ,in quantity determinedaccording to engine loading, with admission initiated and completed inaperiod of relatively low cylinder compression (luring the compressionstroke of the piston.

Prior to' fuel combustion, the major portion of the, gaseous fuel chargeso admitted, is retained in .the auxiliary space, and during thecompression cycle of the engine, is thoroughly mixed withcylindercombustion air forced into the auxgaseous fuel-air mixture. Combustionof the gaseous fuel charge, as compressedin the auxiliary space, iseffected in a positive manner by an igniting charge of a liquid fuel'admittedby' solid injection directly into the cylinder 'combus'tionspace, with admission of the liquid fuel timed to occur near the end ofthe piston compression stroke thereby affording compressionmy. ofigniting liquid fuel consumption, that the quantity of, the liquid fuelignitingcharge so injectedbepreferably less than that quantity de-"jtermined to be j ust sufficient for operating the engine at ratedidling speed under no loadwhen supplied withjsuch liquid fuel alone.

p r v a a important" Fig. 2 is a view similar to Fig. 1 but ShQWl 3 clims, (01. 123-27) iliary space along with whatever gas may initial- -lyreach the cylinder space, to result in a rich present invention toprovide, 'inconnection with an internal combustion engine of the generalcharacter above pointed out, means for supplying liquid and gaseousfuels thereto whereby the engine may be operated oneither the liquidfuel or gaseous fuel accompanied by a small combustion initiatingquantity or pilot charge of the liquid fuel. 7

Another important object of this invention resides in the improvedconstruction, arrangement and operation of control agencies for use withan internal combustion engine oftwo-cyCle diesel type whereby theutilization of a liquid fuel for starting and agaseous fuel for normalload opwhich is insufficient of itselfto maintain the operation oftheengine at no load idling conditions. I 1

A further object is to provide a dual fuel engine of diesel type whichwill operate effectively on liquid or gaseous fuels, and in which a.fuel supply selectivity control system is provided to effect rapid andpositive conversion of the engine for operation on either fuel, throughcontrol responsive means including an engine speed responsive governor,in control of the supply of the liquid and gaseous fuels.

Other objects of theinvention reside in the new and useful combinationof control means and elements associated with an internal combustionengine constructed in .such manner as. to be capable of conversion froma liquid fuel combustion to a gaseous fuel combustion engine operatingonthe diesel cycle, andin the improvements .relating to the features ofconstruction and operation of certain elements of mechanism incorporatedin the control system.

The invention in a preferred form has been disclosed in the accompanyingdrawing, in which:

character, the control system being shownas conditioned for norma1 airstarting;

more advanced phase of the control system suitable for idling operationof the engine as a diesel;

Fig. 3 is still a further schematic view showing the control systemconditioned to permit conversion of the engine for operation on gaseousfuel with pilot-ignition liquid fuel supply;

Fig. 4 illustrates in schematic form the condition of the control systemwhen the engine is to be shut down;

Fig. 5 is a fragmentary detail view partly in section, of a safetydevice for use with the present engine arrangement;

Fig. 6 is an elevational view of a liquid fue pump construction in whichportions of, the pump casing have been broken away to show certainimportant features which contribute to the successful operation of thepresent engine;

Fig. 7 is a view of the pump plunger head development in which thevariable cut-off scroll contour is shown to advan a 2c and hence beexhausted to atmosphere through Fig. 8 is a sectional detail view takenat line 8--8 in Fig. 6;

Fig. 9 is a fragmentary view of the liquid fuel pump control means andactuator as the same would appear with the engine running atapproximately rated idling speed with no load;

Fig. 10 is a view similar to Fig. 9 but showing the liquid fuel pumpcontrol at its pilot fuel charge delivery setting, and

Fig. 11 is a fragmentary sectional view of the cylinder and headassembly illustrating details of the auxiliary combustion chamber andasso- -ciated parts.

Turning now to the drawings illustrating a preferred form which thepresent control system may take, Fig. 1 shows the system in applicationto a two-cycle diesel engine providing .a cylinder block structurehaving one or more cylinders, as the cylinder 35, cylinder head 36, anauxiliary combustion chamber means 31 for each cylinder,

-8D. In addition the engine assembly includes an air start system, aliquid fuel supply system, a

gaseous fuel supply system and a selectivity control system whereby theaforementioned systems may be brought into and out of eifectiveoperation all as will be explained in more detail hereafter.

Air eta-rt system Referring further to Fig. 1, it will be observed thata main compressed air supply line to connected with a principal sourceof compressed air (not shown) leads to an air relay valve 4|, and

.from the latter to an air header line 43 which .in the instance of amulti-cylinder engine, ex-

tends along the engine adjacent each of the cylinders 35. From thisheader, air is conducted through a branch line 44 to the cylinder head36 and then through an internal passage 45 formed in such head to an airoperated admission valve. This latter valve assembly is of generallyconventional construction and as shown diagrammatically in Fig. 1,includes a housing 46, a piston element 41 reciprocable'in the chamberformed in housing 46 and directly connected to 7 'the stem of poppetvalve 43. A coiled spring 49 is provided for maintaining the poppetvalve 48 closed except at such times as air at header pressure isadmitted to the space above the piston 41 as'will appear presently. '75

The air relay valve 41 comprises a housing suitably formed to provide aninlet chamber 5!, an outlet chamber 52 and a pilot piston chamber 53.Between the air inlet and outlet chambers is mounted a poppet valve 54having a valve stem 56 and normally spring urged to closed positionrelative to the passage or port 6|. The pilot piston 62 movably mountedin chamber 53, is adapted upon upward movement to abut the free end ofthe poppet valve stem 56 and move the valve to open the port 6! betweenair inlet and outlet chambers 5| and 52 respectively. Coincident withthis movement of the pilot piston 62, the upper peripheral surface ofthe pilot piston closes a port 65 formed between chamber 52 and anannular chamber 66 surrounding the pilot piston chamber 53, thus cuttingoff communication between chambers 52 and 66 so that air admitted to theformer cannot flow into the latter relief port 51 formed through theouter wall of the chamber 66.

Effective operation of the air relay valve 4| to supply air to header 43is obtained through the use of a relay control valve such as the oneshown at 68 in which the valve housing is formed with an air inletchamber 10, an air outlet chamber H and an intervening port controlledby a poppet valve 13 which is slidably mounted in the housing by meansof the enlarged stem 14. The poppet valve 13 is normally spring urged toclosed position; Air supplied to the inlet chamber 10 of this relaycontrol valve is obtained from a suitable point in the inlet chamber 5!of the air relay valve, as by the conduit 11. As a result, when poppetvalve 13 of the control valve 68 is opened,'by means to be notedpresently, the air at line pressure will pass to outlet chamber II ,andinto a branch line or conduit 18 for delivery to the pilot pistonchamber 53 in air relay valve housing, as at the bottom of the chamberbelow the pilot piston 62. The air admitted to this chamber at linepressure, is sufficient to open the poppet valve 54 against the force ofits spring bias and the pressure of the air in inlet chamber 5|. Thusair flows into chamber 52 and is supplied to the main header 43 and toeach of the branch lines 44 for admission to the cylinders to impart astarting rotational effort to the pistons reciprocable therein, one suchpiston being shown in Fig. 1.

Engine starting air is admitted to the cylinders in the sequence ororder determined therefor, and accordingly an engine driven airdistributor device 82 is arranged to have its rotor element (not shown)driven from the engine camshaft which in the disclosure of Fig. 1 isindicated schematically at 83. The distributor receives its supply ofcompressed air from supply conduit 84 which is controlled by adistributor control valve 85 structurally similar to the relay controlvalve 68 described above. Thus, the valve 85 is formed to provide aninlet chamber 86, an outlet chamber 81, and a poppet type valvecontrolling communication between the chambers and which is providedwith an enlarged stem 9! projecting into the path of operating means,later to be described.

' The poppet valve'is normally spring urged to a closed position. Thevalve 85'receives its'supply of air under pressure through conduit 94frame tapped connection at outlet chamber 52 of relay valve 4!, and atsuch times as the poppet valve 90 is open, air, will be delivered fromthe valve 1 outlet chamber '81 to conduit 84 for supply to. the airdistributor device 82. In the usual distributor 5 construction the rotorelement (not shown) is adapted to deliver air to each one of a plurality'ofb'ranch line's, as the one shown -at'-95,;in' a predetermined orderor sequence. the desired effectof opening the air admission valves 46 at'the respectivecylinders 35 such that line air pressure frombranch-conduits 44 may enter the cylinders successively to impart thenecessary starting impulse for initiating engine crankshaft The presentair startingsystem also includes means for isolating the auxiliarycombustion chamber-means 3l-from the main'combustion space'incylinder35. As shown by Figs. 1 and 11 the cylinderhead 36isprovidedwith anauxiliary cylinder means 38 "comprising a tubular-member 35' having a"reduced diameter portion 91 extendinginto a socket or thimble means 98secured in the cylinderhead 35 such that a passage 93 I 'formed inthe'lower end of the socket means communicate's with th'e'main cylindercombustion space at itsidwerend and'opens into a small chamber I at itsupper end; The chamber I00 'is placed in open-communication through passage'IOI' with'the interior' chamber 39 proper of auxiliarycombustionmeans 31; asshown'. The auxiliary cylinder means 38 contains asmallpiston I02' slidably movable therein foractuation of a valveelement I03 through abutment with the upper "end of the valve stem I04,the latter being guided in a tubular sleeve I and constantly urged in anupward direction by means of spring I06 which pressesagainst the stemcollar I0'I.

' Thejthreaded cylinder cap I08 is apertured to receive one end of anair supply conduit I09 which, in turn, is connected at its opposite endwith the engine starting air"bra'nch conduit or line 44 such that air atline pressure may force piston I02 downwardly-thus se'atingthe valveelement I 03 over passage 03, thereby isolating the'auxiliary combustionchamber 39' from the main combustion space. In an engine of thepresentcharacter it is necessary, say during the starting'and warm-upperiod when the engine is fo'perating'as a diesel, to limit the volumeof the combustion space to that provided in the main cylinder 35. Thusvalve element I03 serves the purpose of isolating the auxiliarycombustion space, and accordingly assumes the position shown in Figs. 1and 2 during the starting pe- Liquidjuel system With reference toFigs.-l and -6 t'o 10,a liquid fuel pump I I I which may be mounted onthe'engine frame structure in any convenient manner, is providedfor eachcylinder 35 and-has a'camshaft operated reciprocable plunger II2 wherebyliquidfuel from a supply header II3 may be inducted through branch feedline H4 and periodically expelledat the proper injection pressurethrough discharge conduit H5. The fuel thus 'ur'ged through conduit H5is directed, bymeans "ofthe' injector valve I I0 set in" the head 36,into the main combustion chamber as a high velocity -jet*which is theusual practice in solid injection diesel engines. The quantity of"liquid fuel so injected at each working stroke of the pump plunger H2is regulated by a control rack II6 slidably carried in the pump housing,as shown in Figs. .6 and 8, and constantly urged in a direction toprevent fuel .delivery by a spring I I]. The rack H0 has a series ofteeth II8 thereon for meshing engagement with a plunger rotating piniongear I20. As will appear presentter shut-off gas valve member I33.chamber I34 of this valve member is connected type fuel metering valveelement I4 I.

6 ly, the' control rack has a longitudinal slot I2I formed therein forreceiving a stop pin I22 such that the maximum travel of' the rack maybe predetermined for a desired rangeof fuel variation designated by thegraduation marks or indicia scribed on the rack body in the mannershown. A pointer element I23 (Fig. 8) issecured to the pump housing inposition to cooperate with the rack indicia so that the rack setting maybe 'observedat all times. 'The above described fuel pump is well knowninthe' art, but for present purposes it has been modified with respectto the character of the plunger head. The preferred modification may'b'e-seen in Figs. 6 and '7, wherein the head portion of the plunger II2, while retaining the usual flat head face I25 for determining aconstant begin ningof fuel injection-relative to closure of thefuel'supply port I 26, is suitably formed to provide a helicallydirected cut-off edge I21 having a flat or constant cut-off edge zoneI28 for determining minimum fuel delivery. The plunger -I I2 is suitablyunder cut in a zone below the helical edge I2'I'to provide an annularrelief groove I23 for the usual purpose of determining the end of theeffective fuel delivery stroke. A cut-off slot I30 directedlongitudinally'of the plunger is-also provided for determining no fueldelivery when the plungeris rotated to bring the slot into reg istrywith the inlet port I26. In an engine of the present character where apilot-injection of liquid fuel is required, it is essential to providesuch a flat zone I28 on the usual helical cut-off edge I 21 whereby tocompensate for variations in the manufacturing tolerances relative tothe forming of the-rack slot I2I and cooperating stop pin I22, andassure the attainment of a minimum pilot 'fuel delivery setting for thepump. Moreover, when initially installing the several fuel pumps III, itwill be seen that the pilot-injection setting of each thereof may bereadily attained with a balanced relationship for equal fuel injectionaction and consequent improvement in the operation of the engine.

' Gaseous fuel system Referring now to the gaseous fuel system. it canbe seen that the main gaseous fuel conduit I 3I leading from a, remotesource (not shown) is connected to the inlet chamber I32 of a mas- Theoutlet by a main gaseous fuel header I35 andbranch conduit I33 with theported inlet housing. I31 forming a part of the general structure of theauxiliary combustion means 31 (Fig. 11). At each ofthe cylinders thehousing I3! is suitably bored.transversely of the gas inlet passage I38(Fig. 11) to provide a cavity I40 for a rotary This valve is operativelysecured therein and is suitably formed such that a slotted portl42 mayeffe'ce tively open or close the passage I38 through its relationshipwith the cut-off edge I39between the passage and valve cavity. At thedelivery sideof the metering valve I4I the passage I43 communicates witha poppet valve chamber I44 and the auxiliary combustion chamber 33therebeyond.

The metering valve element I4I has a'shaft extending outwardly of thehousing I31 for connection with an operating lever arm I46 such that thevalve may be rotated for control of the quantity .of' gaseous fuelflowing. through the slotted. port I42 for ultimate delivery to the aux-7 iliary combustion chamber means 31., The lever I'46is actuated througha safety link member I41 (Figs. 1 and it in turn being actuated by acontrol lever I48 associated with the control system later. to bedescribed. The safety link I41 is so constructed that should a meteringvalve element stick, or refuse to work as intended, the remainder of thevalve elements, as in amulti-cylinder engine, may still function betweena fuel cut-on position and the setting assumed by the sticking valveelement. Thus the engine may be shut down until the difliculty iscorrected.

In the preferred form (Fig. 5) the safety link comprises a tubularmember I50 having a plug element I5I fixed in one end by a cross pinI52, an internally positioned reduced diameter sleeve I53 threadedlysecured in the opposite end of the member I50 by means of the baseflange formation I54, and a rod element I55 telescopingthe sleeve I53and extending normally the length of the member I50 where an enlarged,flanged head I56 abuts the plug element I5I to provide a solidconnection in one direction of motion of the link. The rod element,however, is normally held in solid abutment with plug I5I by a springI51 which contacts the flanged head I56 of the rod and abuts the baseflange I54 of the sleeve I53 in the annular space formed between thesleeve and tubularmember I50. The ,7

plus I5I is connected by clevis I58 with operating lever I46 and the rodI55 is connected to the control lever I58 by a second clevis member I59.The required spring force is normally calculated on the basis of itsadequacy to maintain rod head I56 in contact with the plug I5I, but ifthe lever I48 becomes immobile the yielding nature of the spring I51will allow relative movement' between rod I55 and member I50.

Turning again to Fig. 11 it will be observed ber I66 secured to thestem. Rocker arm I64,

pivotall mounted on a bracket I81, is actuated by a push rod I68extending to a cam follower element I89, in turn actuated by a suitablecam on camshaft 83.

Since the present engine may be started up as a diesel and thenconverted to the utilization of a gaseous fuel, means in the form of afluid pressure relay system has been provided to open the master gasvalve I33. The relay system (Fig. 1) includes a master sequence valveI1I receivingfluid under pressure from an engine driven pump, I12through conduit I13. A slide valve I14 having spaced piston elements Iand I16 is movably mounted in the valve casing such that piston elementI15 may close or open the port communicating with the fluid supply lineI13 at predetermined times controlled by a plunger pin I19 mechanicallyheld in opposition to the urging of a spring I11 positioned at theopposite end of the valve I14 relative to the pin I19. In the positionshown, valve piston element I15 has cut on fluid supply line I13, butwhen the valve is allowed to move upwardly, by means later appearing,the line I13 communicates with the assumes 8 annular valvechamber formedbetween piston elements I15 and I16, and, as a result, pressure fluidwill then flow out of the valve chamber to conduit I88. The mastersequence valve I'll also is provided with a bleed line I8I connectedthereto for control by the lower valve piston element I16. This latterpiston element is so spaced relative to piston element I15 as toprovide.communication between the valve chamber and bleed line I8I. when supplyline I13 is cut ofi. The conduit I88 being open between each pistonelement of the slide valve I14 is therefore at all times incommunication with the annular valve chamber and selectively incommunication through this chamber with the fluid pressure supply lineI13 or the bleed line I8I. Assuming now that the engine isrotating andthe slide valve I14 has been. allowed to move upwardly, by means laterto be noted, to a position in which fluid under pressure can flow toconduit I80. it will be seen that suchfluid passes along the saidconduit to a fluid relay valve I82 which is structurally similar to themaster sequence valve above described. The relay valve is provided with,a slide element I83 having spaced piston valve elements I84 and I85 todefine an intervening annular chamber I86 with the valve body. Hereagain the relay valve is provided with a plunger pin I81 mechanicallyurged in opposition to a spring element I96, by means external to thevalve body as will appear presently, such that the piston element I84per. mits communication between conduit I88 and the chamber I86. In thisposition the piston element I85 closes a valve port communicating withan emergency bleed line I88 with the result that fluid under pressure inchamber I86 will pass outwardly through the intermediate opening, intoconduit I88 and into a valve operating motor cylinder I80, the latterassociated with the master gas fuel valve I34. The pressure fluidentering cylinder I90 will force the motor piston I! in a direction (tothe left in Fig. 1). to abut a valve stem I92 on master poppet valve I93and open the same to allow gaseous fuel to pass from inlet chamber I32to outlet chamber I34 and hence to the main supply header I35 for theengine. The poppet valve I93 is, nor-.- mally spring urged in a closingdirection, as shown.

Under normal conditions of engine operation the relay valve I82 willhave its slide valve I83 held in the position shown in Fig. -1 whichresults in the conduit I88 being both a supply and return or bleed linerelative to the master sequence valve I1I, since the latter valve ismade subject to active control means later appearing.

In the arrangement of the fluid pressure system just described the fluidbleed lines I8I and I89 connect with conveniently located fluid operateddevices or engine operating adjuncts. However, in the schematic layoutof Fig. 1 the disclosure indicates a fluid sump I95 to which the bleedlines extend. Similarly the fluid supply pump I12 is placed in this sumpto draw up the fluid contained therein. It is most convenient to utilizeoil as the fluid for the described system for obvious reasons,

Engine control system In the course of the foregoing descriptionfrequent mention has been made of control means to which portions of theabove systems are re- 'Sponsive for proper operation and to provide adifierent set of conditions for engine starting,

'9 operating as a diesel on liquid fuel and for normal gaseous fueloperation. Such a control sys- Item to be adequate for thepresentpurpose may be described as comprising a manually operated cam rotatesin a plane containing the valve plunger element I19 of master sequencevalve 11 l. Shaft 28 also carries a second cam 204 for movement in aplane containing both of the poppet valve stems 14 and 9| respectivelyassociated with the relay control valve 58 and distributor control valve85. Y

,It will be noted that the selector cam 29 is formed with a constantradius cam face 2 of considerable arcuate extent which merges abruptlyat the lower side with a fiat cam face 2 l2, and at the upper side witha second flat cam face 2 l3. Each of these flat cam faces extendschordwise of the cam disc and merges with a second arcuate cam face 214,the radius of which is equal to the radius of the first cam face 2| I.Noting now the control handle positions shown inFigs. 1 and 2, it willbe clear that for positions designated "Start 1 and Start 2 the cam face2| I will engage the head of plunger element I19 for the master sequencevalve Ill and mechanically move the same inwardly of the valve such thatthe piston valve element I15 will cut-off the supply of pressure fluidto the valve chamber. This effectively disables the supply of gaseousfuel-by preventing pressure fluid from actuating the master shut-off gasvalve I33 to open position. Now when the control handle 2! is moved toposition "Run (Fig. 3) the 'flat cam face 2l2 is moved over the valveplunger element I19 and permits the same to move outwardly so that thevalve piston 115 now uncovers the pressure fluid inlet conduit I13 andvalve piston I16 closes'the bleed line (8. In this condition pressurefluid can pass to the actuator cylinder E90 and; open the mastershut-off gas valve. -Upon' further movement of the control handle to theStop position (Fig. 4) arcuate cam face 2l4 contacts I the plunger I19to force the same inwardly thus repositioning the valve piston elementsI15- and i16 tocut oif supply of pressure fluid and open the. fluidbleed line whereupon the master shutoff gas valve I33 will close. In thedisclosure of Fig. 1, selector cam 29 is rotated counterclockwisethrough the several positionsnot-ed. Similarly, the second cam 204 willbe rotated in a counterclockwise sense-through the same-angular degree,as each of these cams 29 .and 204 is carried on the common shaft 28.

The form of cam 204 in the profile thereof presents a constant radiuscam face 2 l 6 which extends over substantially one quarter of the camdisc. base circle. This cam face 2l6 merges with a raised lobe 2|!andit, in turn'merges with a relief cam face 2|3 which is substantiallyconstant over the remainder of the cam disc circle except in the zonewhere it rises slightly and mergeswith the first mentioned cam face 216.As has been noted, cam 204 is positioned to engage each of the valvestems l4 and 9| of the relay control valve 68 and distributor control.valve respectively, for the purpose of controlling the sequentialopening or closing of these valves. For example, when control handle 2'!(Fig. 1) is moved to Start 1 position, cam' 204 will be re tated to aposition in which cam lobe 2|! opens valve and cam face 2l6 opens valve13. 'In the Start 2 position which is shown in-Fig. 2, the cam lobe-2|!will move away from stemfll permitting closure of valve 32, but camface, 216 remains effective to hold valve 13 open. Further rotation ofhandle 2 tothe Run position (Fig. 3) will permit valve 13 to close asthe cam relief face 218 is now under the associated valve stem 14. Valve90 is not disturbed at this latter time and consequently remainsclosedsince cam face 2; is out of workingcontact with its valve stem 9|. Forcontrol handle position "at. Stop (Fig. 4) each of the air valvesremains clo'sed'as will be clearly evident upon inspection.

It should now be recognized that upon-positionment of the control handle21 in each ofits noted settings and upon the corresponding rota tion ofshaft 28, each of the cam members '2 9- and 204 is adaptedto.afiord'controlresponse of cer tain valvular membersof the enginestarting and fuel supply systems for determining proper func tioningthereof. I v

The automatically responsive operating control system, forming a part ofthe general engine-control system, includes a control shaft 220, shownin broken linein each of Figs. 1 w 4 extending the length of the engineand rotatably supported by suitable bearings (not shown). Thisshaft,hereinafter called a fuel control shaft, is rotationally adjusted by anengine speed responsive governor 22| of any conventional type,butpreferably of oil operated character, through the expedient of asafety lever connected'between the governor arm 222 and the shaft 220.Essentially the safety lever includes a first'cr'ank arm 22 3 fixed toshaft 220, and an intermediate crank arm 224 sleeved on' the shaft 220and adapted'for limited angular movement relative to the shaft and crankarm 223. Normally these lever arms 223 and 224 areheld against relativemovement by a tension spring 228, but thespr'ing will yield to permitgovernor movement of arm 22 4 without corresponding movement of arm- 223under a condition hereinafter to be referred to, when the control shaft220 is held againstrotation. Inter mediate lever 224 is linked with thegovernor operating'arm 222 by anadjustable member 229 such that as thegovernor ar'm "222 moves clockwise (Fig. 1) say from its full fuelposition toward a no fuel position the' l ever system 223, 224 will movecounterclockwise, and the fuel control shaft will also rotatecounterclockwis'e in response to such governor action.

The fuel .control shaft 220 has distributed along its length the several:leverar ms' I48. (only one being shown) which are fixed or clampedthereto in positions one opposite each cylinder to effect simultaneousoperation of each of I thegaseous fuel metering valves; before noted,uponfrotational adjustment of the shaft by the governor 221. Moreoverthis fuel control shaft carries liquid fuel, pump control .levers 23l(only one shown) clamped thereto in proper positions, one opposite eachcylinder to contact theend ofuthe respective pump control racks 6' forsimultaneous operation thereof. In Fig.6, a typical pump control lever23l is shown as provided with an adjustable tappet element 232 threaded1 1 through the lever andheld'in set position by the lock, nut 233.

Rotation of the fuel control shaft 228 in a counterclockwise sense fromthe position showing in Fig. 1 will swing the lever 23I (Fig. 5) in adirection to reduce the fuel output of the pump ill by permitting thespring II! to move the pump rack I I6 to the right, and normally at zerofuel output the pump plunger relief slot I30 registers with the fuelinlet port I26, as is well understood. However, in the present instancewhere a small pilot-ignition charge of liquid fuel is required forcombustion of the gaseous fuel, it i not desired that the liquid fuelpump plunger be returnable to a zero fuel delivery position. Thus thestop pin I22 and rack slot I2! cooperate to maintain a predeterminedminimum delivery and to prevent attainment of a zero fuel deliverysetting.

As an example of the fuel pump operation rela tive to governor settingof the control shaft 220, Fig. 6 illustrates approximately the relativepositions of pump rack H6 and control lever 23! at a time when theengine commences to fire on liquid fuel as a diesel. The pump willordinarily deliver more fuel at starting than is necessary to maintainrated speed at no load and accordingly under automatic governor responselever 23 I will swing in a counterclockwise direction to allow the rackto move in a fuel decreasing direction until the correct fuel quantityfor no load and rated speed is attained, as illustrated in Fig. 9. Whenthe engine is converted to the use of a gaseous fuel there is amomentary period when the liquid and gaseous fuel supply is in excess ofthe immediate requirements to maintain rated speed. Consequently, thegovernor will again move to reduce the fuel supply by furthercounterclockwise rotation of shaft 220 and in so doing lever arm 23Iwill swing away from and break contact with the pump control rack lit,thus conditioning the fuel pump III for minimum or pilot liquid fueldelivery. Fig. illustrates this latter condition at the approximatemoment when control lever 23! is about to break contact with the fuelcontrol rack H6, after which the engine will be operated with gaseousfuel the combustion of which is effected by the pilot charge of liquidfuel delivered by. the fuel Simultaneously with the above describedcontrol of the liquid fuel pump, as by rotational adjustment of. thefuel control shaft 220, the gaseous fuel metering valve (Fig. 11) MI isrotationally adjusted to control the quantity of such fuel admitted,provided that the master gas valve I33 is open to supply gaseous fuel toheader, I35 and branch lines I36. In view of Fig. 11 the full lineposition of the slotted orifice I42 in the metering valve corresponds toan initial governor setting at its full fuel position. However, duringthe period of 'liquid'fuel diesel starting of the engine and adjustmentof the liquid fuel pump I l I to the rack setting of Fig. 9, themetering valve I4I will be moved to the dotted outline .position of itsslotted orifice I42 which is still within the range of potential fuelgaseous fuel admission. Gaseous fuel not being supplied at this time dueto a preferred control condition presently to appear, the gaseous fuelmetering valve motion has no actual control function and simply movestoward its initial fuel metering position. This movement is hereinreferred to as the over travel or non-metering range adjustment of themetering valve.

Now with the metering valve slot 142 lnits dotted outline position ofFig. 11 and the fuel pump rack set as in Fig. 9 for rated speedat noload, should gaseous fuel be supplied to the valve I4I the complementaryquantities of liquid and gaseous fuel will cause an engine speedincrease which immediately'will be sensed by the governor 22 I. Governorresponse will rotate the fuel control shaft 220 in its fuel decreasingor counterclockwise direction to set the liquid fuel pump rack at itspilot charge position (Fig. 10), and to rotate the gaseous fuel meteringvalve in a clockwise direction such that the slotted orifice I42 beginsto pass under the cut-off edge I39 of passage I38 (Fig. 11) to restrictthe quantity of fuel flowing therethrough. However, the metering valveorifice I42 will still be open to an extent closely approximating a wideopen setting and the governor 22I accordingly will continue valverotation to reduce the gaseous fuel quantity being admitted to passage443. As a result the fuel control shaft 229 will now swing control lever23I out of contact with the liquid fuel pump rack H6 and the governorthereafter will be operative with respect to the gaseous fuel meteringvalve I4I alone.

When this last described condition is met the engine will be fullyconverted to the combustion of gaseous fuel with a substantiallyconstant pilot-ignition charge of liquid fuel supplied by the pump III.Once fully converted to gaseous fuel, any load variations-on the enginewill be met by automatic governor response to adjust the gaseous fuelmetering valve MI in a direction toward or away from full open setting.This condition is determined when the control handle 21 is in its Runposition (Fig. 3), and as a precaution against rotation of the fuelcontrol shaft 220 in a clockwise direction and to an extent sufficientto reestablish the fuel pump control levers 23I in contact with the pumpracks I I6 for moving the same inwardly to increase the quantity ofliquid fuel supplied, the fuel control shaft 220 carries a lockout lever236 (Fig. 3) fixed thereto in position in the plane of the cam 29 sothat the constant radius cam face 2 l I will contact the end of lever236 and prevent clockwise rotation of the fuel control shaft 220 beyonda setting corresponding to a wide open position of the gaseous fuelmetering valve MI and asetting in which control lever 23 I is just outof abutment with the fuel pump rack! I5. With the handle 21 in either ofits Start 1 or Start 2 positions, Figs. 1 and 2 respectively, the flatchordwise face 2 I3 of cam 2-9 is'positioned adjacent the lock-out lever238 and hence will permit full rotational adjustment of the fuel controlshaft 228. In the Run and Stop positions of cam 29, Figs. 3 and 4respectively', the cam face 2 will be underthe lock-out lever 2 36 to'prevent the rotation of fuel control shaft 220 to increase fuel deliveryfrom the liquid fuel pumps III above the predetermined smallpilot-ignition charge which in itself is determined to be insufficientto continue engine operation even at rated idling speed, no loadconditions. I j

A full and complete understanding of the na-'- ture and function of thepresent engine control system as above described, may be found uponreference to Figs. 1 through 4 in which the essential parts andmechanism have been only diagrammatically set out, these viewsdisclosing the successive order of events as they occur with referenceto the respective control positions of handie 21.

" control'setttng start 1 It is convenient to assume here that theengine is initially shutdown and that the operator, finding the controlhandle 2'! in the.Stop position, "moves the same in a clockwisedirection to the Start 1 limit of its travel, as shown in Fig. 1,thereby rotating the shaft 28 and the cams 29 and 294. Cam'29 isthereforeset with its face 2| I in position to hold the plunger I19 ofmaster sequence valve I '|I in its innermost position such that thepiston element I cuts off pressure fluid admission line I13, to assure aclosed condition of master gas valve I33 even though the enginecrankshaft is not revolving and fluid under pressure from pump. I12 isnot available. It should benoted that the fluid pressure operated typegovernor 22I is inoperative also and accordingly the governor lever arm222 will be in its fuel shut-off position, normally downwardly directedfrom the position shown in Fig, 1. In keeping with the fuelshut-offposition of arm 222, the fuel controlshaft will be rotated sothat the fuel pump control leyer 231 thereon is out of contact displacedina counterclockwise direction from that shown, to move the meteringvalve IM to tributor control valve85 to open the poppet 98. v

The immediate efiect produced upon opening of the air relay valve 68 isto force the pilot piston vI52 in the air relay valve 4I inwardlythereby opening the main air admission valve 54. This occurs by reason.of the flow of compressed air from supply line-.4tl to conduit 11,through relay control valve 68 to conduit I8 and into chamber 53 of theair relay valve. The compressed air at line'pressure-flows to the airheader 43 and to the respective branchlines 44 at each cylinder. Oncethe main air relay valve M is opened, as just described, pressure airflows into the conduit 94- and to and through the opendistributorcontrol valve 85 to conduit 84 for delivery to the air dis- 7 tributor92. The-latter device, even though not rotating, will usually be foundto have an'open feed line such as 95 whereby compressed air may flow tothe air starting-admission valve 46 to open the associated poppet valve4 8. Compressed air admitted to the chamber above piston 80 willinitiate crankshaft rotation and thus start rotation of the airdistributor to supply air to others of the air start valves 46 forcontinuing the rotational eifort of the crankshaft as is wellunderstood.

During the occurrence of the foregoing events to achieve rotation of theengine crankshaft as Well as its camshaft, line air will also pass intothe conduit; I09 leading to the auxiliary cylinder means 38 for drivingpiston I02 downwardly to seat valve I03 whereby the auxiliary combustionchamber 39 is effectively isolated from the main combustion chamber in,cylinder'25. With this actuation of piston I02 completed, the engine isfully adapted to begin operation as a diesel.

' Again considering the governor 22I, it can be appreciatedthat-crankshaft rotation will make available pressure fluid forenergizing the governor to move its control arm 222 to the full fuelposition shown in Fig. l. Concurrently the fuel control shaft 220 willmove from the no fuelposition, above described, to the full fuelposition of the drawing. Thus the fuel pump I I I can deliver itsmaximum quantity of fuel to the injector valve H0 for injection to thecylinder combustion chamber. At the same time the gaseous fuel meteringvalve I4I will bemoved to its non-metering range of adjustment, but nogaseous fuel is made available since the master gas valve I33 is heldclosed or in a gaseous fuel supply disabling position due to lack ofpressure fluid on piston I9 I.

Liquid fuel being available at the injector valve Illl, the engine wil1commence to fire as a diesel and upon sufficient speed pick-up, theoperator next moves control handle 21 to the Start 2 p05 sition. It ispossible that before handle 21 is shifted the engine speed will exceedits rated idling condition, and in such event governor 22I willautomatically move fuel control shaft 220 in a counterclockwisedirection to reduce the quantity of fuel delivered by pump I I I.Briefly summarizing the control conditions existing when the controlhandle 21 is movedto Start 1, it is evident from the foregoingdiscussion that:

1. The self-closing fluid operated master gas valve I33 is closed duetolack of fluid under pressure; l 2. The engine starting air system isfully operative'to admit air at line pressure to at least one cylinderfor the initial impulse to rotate the crankshaft;

3. The air relay valve M is open to supply starting air;

4. The auxiliary combustion chamber 39 is isolated by closure of airoperated valve 03;

a 5. The liquid fuel pump I I I is regulated by th governor 22I to astarting delivery condition, and 6. The gaseous fuel metering valve isrotated to an over travel position in a non-metering range, but is notsupplied with gaseous fuel due -t closure of the master gas valve I33.Obviously these conditions either exist initially or are brought intobeing substantially simul' taneously, due allowance being made for thein herent time lag in the fluid pressure'systems and for r'esponseiofthe governor to effect fuel control shaft rotation. I

Control setting Start '2 Referring now .to Fig; 2 in which the controlhandle 21 is shown at its Start 2 setting, it will be observed that thecam 29 on shaft 28 remains effective through camface 2i I to holdthe-master sequence valve I'II in position to prevent the sup-- ply ofpressure fluid for opening the mastergas valve- I33; However, cam zill'will now bein position to permit closure ofthe distributor con= trolvalve and render inoperative the air distributor 82 to open airstartvalve 46', since start ing air is no longer required. Cam 204 will'still remain effective through its cam face 2i 6 to hold the relaycontrol valve 68 open and assure continued closure ofthe valve I03 tohold the auxil-- iary combustion chamber 39 out of communication withthe main combustion spa'ce'in cylinder 35. L I w 'Thee'ngin'e is nowoperating-as. a dieseland the governor22l will rotationally adjust thefuel con trol shaft220 to set the rack H6 of liquid .fuel pump II I atthe proper position for rated idling speed with no load. During thisperiod of liquid fuel control by the governor, the gaseous fuel met'ering'valve I4I will also-be adjusted tothe set ting shown in Fig. 11,particularly the dotted line position of the slotted orifice I 42therein. Since no gaseous fuel is available atthis time, the me teringvalve will be adjusted through'its over travel or non-metering rangetoward or away from a position of potential full gaseous fuel admission.Thus it will appear that the gaseous fuel metering valve is initiallyrotationally adjusted through an over travel or non-metering range, inwhich no fuel throttling action occurs due to lack of a supply ofgaseous fuel, and toward a control setting in which the metering valveis capable of producing a throttling effect upon further rotationaladjustment. During this initial metering valve over travel adjustment,the liquid fuel pump I I I is simultaneously adjusted from a full openstarting delivery setting of the control rack II6 toward a reduced fueldelivery setting which is determined to be sufficient for maintainingthe engine at rated speed withno load. Thus the engine speed responsivegovernor 22I is called upon to perform the function of adjusting thegaseous fuel metering valve MI and 'theliquid fuel pump I I Isimultaneously and in the manner above described.

In the preferred arrangement, where the engine is started under no loadas a' diesel, the governor operating arm 222 is angularly displaceablefrom its position shown in Fig. 1, and corresponding to maximum supplyof liquid fuel, toward a position of reduced liquid supply which isattained upon clockwise rotation thereof as viewed in the drawing.During this n loadengine operating period in which the metering valve MIand fuel pump rack I I6 are adjusted as above pointed out, onlyaninitial portion of the full angular displacement of governor arm 222 isrequired. Therefore and in order to distinguish this initial angulardisplacement of arm 222 from the remaining displacement thereof, it willbe convenient to refer to the full governor arm travel as being dividedinto a first control range or inner angular range of displacement forliquid fuel supply control and a second control 1- range or outerangular range of displacement for gaseous fuel supply control. Aspointed out above, the governor response for the.Start 2 or dieseloperation of the present engine will .be

confined to the first or inner angular range of displacement for thereason that the liquid fuel pump I I I is operative to supply startingfuel and also to supply fuel for maintaining ratedidl'i'ng speed at noload, the gaseous fuel metering'valve MI being adjusted simultaneously.through its over travel or non-metering range toward or away from aposition at which further movement of the fuel control shaft 220 in acounterclockwise direction willmove the slotted valve orifice I42 underthe cut-ofi edge I39.

Accordingly with the control handle 2! moved tothe Start 2 position, thecontrol system will respond such that:

1. The liquid fuel pum I II will be under governorv control anddelivering fuel to keep the engine running at rated speed with no loadapplied; 2. The master gas valve I33 will be closed due to positionmentof the master sequence valve III by cam 2 9;

3. The gaseous fuel metering valve I 4| will be adjusted by the governor22l but will not be ef+ fective as no fuel is delivered thereto;

4. The starting air admission valve means 46 will be renderedinoperative by closure of the distributor control valve 85, and v IControl setting Run Once the engine is operative as a diesel, at its noload, rated idling speed, the operator may convert the engine to gaseousfuel combustion by shifting the control handle 21 into the Run" positionof Fig. 3. Upon such movement of the control handle 21, the cam 29 willbe displaced so that the fiat cam face 2 I2 will allow the mastersequence valve I II to change its position, opening the pressure fluidsupply line I13 and closing the bleed line IBI. Pressure fluid is thenavailable for flow through conduit I80, fluid relay valve IB2 fandconduit I88 to the cylinder I at the master gas valve I33 for openingthe latter valve to enable supply of gaseous fuel to the header I35,branch line I36 and metering valve I4I. Simultaneously with movement ofcam 29, cam 204 will moveto allow closure of the relay con,- trol valve'58 and hence closure of the air relay valve II to discontinue thesupply of compressed air to header 43, branch line 44 and conduit I09.Upon closure of the air relay valve and down: ward movement of the pilotpiston 62, the air vent port 61 will be opened to permit escape" of airfrom the aforementioned header 43 and from line I09, thereby allowingmovement of the auxiliary piston I02 under spring urging to open thevalve I03 and establish communication between the auxiliary combustionchamber 39" and main combustion chamber in cylinder 35. At the time theabove events occur, cam face 2II on cam 29 will move under thelock-outlever 236 and prevent further movement of the fuel control shaft 220 ina clockwise direction to increase the quantity of liquid fueldelivered'by pump II I above that quantity required for pilot ignition,which is' insufficient of itself to maintain engine operation.Therefore, the cam 29 and lock-out lever 23B cooperate to prevent thegovernor from operating with its arm 222 in the first or inner range ofangular displacement or, in other words from again moving in a direction(counterclockwise as viewed in Fig. 2) to effect increasing delivery ofliquid fuel. As a result the fuel pump I I I is positively limited todelivery of only a pilot-ignition fuel charge for the purpose ofinitiating combustion of the gaseous fuel charge admitted by themetering valve I 4| and poppet valve I60 to the chamber 39 in means 31.

1 In the preferred construction of the cam 29 and form of the cam 1surfaces 2 and 2-I2 with respect to the disposition of lock-out lever236 and'master sequence valve I'II respectively, it is intended thatupon rotation of the cam 29 by handle 2'! to the"Run position (Fig. 3)the valve I'IIv will permit opening of the master gas valve I 33. toenable the flow of gaseous fuel to the engine slightly in advance of anymechanical contact between cam surface 2H and the lockout lever 236. Thereason for this is that if the lock-outlever 236 is mechanically movedto shift the fuel control shaft 220 to the minimum liquid fuel. deliverysetting of the pump III ahead of the flow of gaseous fuel through valveI33, the engine may falter or miss-fire with consequent loss of-speed.

I Assuming now that the no load conversion of the engine to gaseous fuelattended by only a pilot-ignition charge of liquid fuel has beeneffected, it will be observed that the gaseous fuel metering valve MI isat its full open setting, thereby admitting more fuel than is required.

117 Accordingly; thergovernor-afl l iwillrrespondiriby movementsotits:armrzzzz :sin .atino tuck-direction which; asnaboveinoted dnaconnectionwith the description: of Start 2Foperatiomrresults in govemorzoperationin: ith secondi or. outer range, of;

Sfiil'21fKEig. l0); and the supplybf gaseous fuel isdieinga establishedupon opening'ofzmaster :valvfe I33:-v by means of fluid.pressureadmitted touthe cylinder 1239; I through appropriate: actuation-:of i

masterscsequence. valve i H the engine will be; H

fullyqconditioned tozutilize-a gaseous fuel. Concurrently. therewith,.thewgovernor control areanOnse-ior moving "the fuel: control shaftlZZ0i will be;;.positively confinedtocthe limits oiitsouter range ofangular displacement of arm222, as by the-glockeout :lever' contactingthe: cam :face 21 for maximum gaseous fuel supply-and the conditionerclosing movement of the metering valve I41 iior throttlingthefuelsupply.

Ineview of the above discussion relating .to the; aunzi p sition; ofcontrol handle v2 hit is appreciatedzthat:

4 1. Theiliquidrfruelpumpr ill is-reduced to the functionotdeliveringionly a-pilot-gignitioncharge ofsfuelifor-wigniting the maincharge of,gaseous f-uelpadmitted to the: auxiliary combustionchamber-39yfor admixture withgcombustion vair from thecylinder-.2..;The:mastervalve 133: isaopened by pressure 3. =-.'Iheauxiliarycombustion chamberis opened upon'retra ction of the valve-1,03 due;toreliefrof compressed-air from auxiliary vcylinder 38 throughatheairrelay -bleed -,port B1, and

4.5mm: gas metering valve 4 this. under governor control: and regulated.to r deliver fuelzas re:- quiredrhy theload onthe engine. 7

-:Itwill Joe appreciated that: the engine, when converted toil-the :useof. gaseousyfuel, may ebereconverted atanyitime i130 .rliquid:fuel.-:operation by, shiftingmthe selectivity :1 control vhandle {tothe start 52 .position; -in which. positionithe: master gas Supply valve133 willxclose and .thecam'ifl zwill mOYEEQWflYufIOm thefloch-outlever236 to permit rotatiom'of fuel-wcontrol -shaft-: 220 into ii-ts :inneltran ezofzdisp-lacement forgreestablishing the constlfOhOl/Brn the, fuelpumps. The: return;- torliquid fuel separation is best accomplished withno load omithel engine; Inthis conversion to liquid :f-uel operation;:thezauxiliary combustion: .ch amber- 9;

will'again be isolated;

"Control-setting Stop fiueli in header- J35 issused. up; thegovernor 22]I fluid-flowing 'fromjthe master sequence valve I-Hwillsautomaticallyicallliar .more ,:fuel-. and-Willfl'flspondibpmmoyingtits arm 2 2 2 inl-a -counterelock wise:rihzo'ction tot rotate the: fuelcontrol :shaf-t 22-0 throughitstoutenrange OLE-movement andvina direction: aimiockwise) :fully-toopen the gaseous fuel metering-watt e HI. esince the;'gaseous-fuelsimply: isrshuta off the; governor willwthen I attempttorcontinueits-movementto-increa-se :fuel but due to theloolz'soutilever 23 iimovingainto contact-with the acam iace. -l of: camra, thexgovernor arm 2-2 2 Wfll'EFbQ prevented-from-moving beyond thewinner limit oftitszputer ra-ngeaofxangulardisplacement and;;:a anesult-,-t he :fuelapump I H cannotxbeadjustedwt -si1pp1'y-:more thanits v, ziilot-ignition charge; ,Thevconsequence of this-action oflockoutiiever ant /will; he: 'to' maintain the minim-um liquid'fuelsupplylyvhich is not of z-itselfsuflicient to nperate the? engine; and?vthe engine (will; then eventually-cease: operating: when the gaseousfuel 1 in the. lheader il35;:is exhausted ior \reduced'to anmconsequential'amount- At :theitime handle 21 :is moved to the StopfDQSitiOILLGBJm'rZQ 4-:will heirotatedsothatthe relay control valveliB-iandsdistributor control valve '85 remain-closed thusigpreventinganypossibility of ahaadm-issionytol-the several: adjunctive elementsof=;the :engineforinitiating starting; In this'position ofithe controlhandle2-lit3is now: appreciated that;

r 1. 1 Thermasterx; gaseous fuel valvev 1:33 will he closed; 1 v

2. Thee-gaseous fuel metering valve-will be moved the; governortowcontinue gaseous fuel delivery from-the ,l-residual 'fuehin :theheader 4-35 1 untilirthe volumeiis insufficientto keep the enginerunningy 3.;The liquid fuelipump lll will -bet-held-to itspiloteignition gpositi'oniof fuel delivery which-is insufficient' ofitself to: keep the engine running,

-. and

4. iThestarting-air systemwillhe held inoperativeby theipositionrofcami204;

-"E1z;gine' overspeed-and safety stops in amengine of theabove 1describedcharacter means haslbeen providedfor stoppingthe engine 7should the needarise; aszin amechanical failure latch. 24.2 .whenthlengine. is in normal operation emer encyoonshouldctheengine attaindangerouslyv highsspeedsl v-With'zreferenee-to-Eigii Lathe engineoverspeed safetywmeohanism may include :aifiuid pressure operated ovispeect governorv Moot-any standard construction, asuitablyeconnected to--the-. engine lube-oil, ,systemrfon supply at oil-and'under, a pressurewhich, is proportionalto the rotational speed ofianengine driventoi-lpumpicnotshown); This overspeed governor conveniently mountedon theenginestructu-re; r15 r equipped -iwith; a main governor.;shaft'-to-which issfixedz-i-at thezexterior of the casing aamovable datch element24:2-.-.,-havingaa notch formed thereon; Thelelement 242-als0 has.-

a z-trip=; finger 24Awformed as an integral portion thereof :fon a-purpose lpresently to appear. This latchielement is'hiasede irsaclockwisetdirectiona-as v-i'ewed'ain Eigalfihyan externalgovernorloading Thetripileverjilis provided also with divergent arms;onearmf 253 'being adapted to contact the.

head of i the'plunger pin f'l '8.'| for 'the'fluidl relay valve lMfaIidthe-other-armlfi l being adap fid T10 contact an element 255 fixed onthe fuel control shaft 220. Springs 256 and 251 respectively attached toarms 253 and 254 of the trip lever 250 serve to urge the lever in aclockwise direction as to an overspeed released position when thegovernor latch 242 is actuated to break contact between the notch oflatch 242 and flange 252. When this occurs, only for engine overspeedconditions, the lever 250 moves clockwise to the limit of its angulardisplacement determined by a suitable adjustable stop element (notshown), thereby releasing the plunger pin I87 and forcibly rotating thefuel control shaft through abutment with the member 255 to a no fueldelivery position. It is preferred that the combined forces of springs256 and 251' be sufiicient to force rotation of the fuel control shaft220 to its no fuel position against the tension spring 228, the latterserving normally to hold arms 223 and 224 in fixed angular relation.Thus the overspeed trip lever 250 may override the fuel control governor22I regardless of the force being exerted on the governor arm 222 andnot be required to return the governor to its no fuel position.

Coincident with the movement of the fuel control shaft to no fuelposition upon overspeed release action of the overspeed governor 248,the fluid relay valve I82 is allowed to shift from its normal setting(Fig. l) to a position in which the piston I84 closes fluid inletconduit I80 and piston I85 opens the bleed conduit I83. The fluidpressure built up in cylinder I90 to hold master gas valve I33 open isthereupon relieved to the bleed conduit and the gaseous fuel supply lineI3I cut off. As a result the gaseous fuel supply is positivelyterminated and only the pilot-ignition charge of liquid fuel isavailable, which in itself is not sufficient to keep the engineoperating.

In the event it is desired to shut down the engine quickly even thoughthere is no overspeed condition or when the overspeed mechanism refusesto function correctly, the trip lever 250 may be forcibly released fromthe holding notch 243 on the latch element 242, by pressing inwardly onthe emergency stop button 260. This stop button is connected by push rod26I with a fitting 262 which is provided with an elongated slot forreceiving a guide pin 264 fixed on the trip lever 250 at a zoneintermediate the ends of the slot. Normally the pin is free to move inthe slot during overspeed operation of the governor 240, but upon inwardmovement of button 260 the fitting slides on pin 264 and a dependingfinger 265 engages tripfinger 244 on latch 242 and pivots the same in adirection to release the trip lever 250 for stopping the engine in themanner before described. I

Aside from the above noted emergency operation of the button 260, it isimportant to note that this means is also employed for re-setting theoverspeed mechanism once-it has been tripped. In so utilizing thisbutton 260, an outward pull thereon will effect engagement of theslotted fitting 262 with pin 264 to result in 20 with modifications and.alterations of structure and rearrangements of control expedients fromthat shown here, and it is the purpose and intent to cover all suchmodifications and alterations as.

may fully and completely come within the spirit and scope of the presentinvention as the same is defined in the appended claims.

What is claimed is:

1. In a dual fuel internal combustion engine of two-cycle type, acylinder and piston therein defining a cylinder combustion chamber, thecylinder having piston-controlled air admission and exhaust ports, meansproviding an auxiliary combustion chamber, a passageway between saidchambers, an engine driven fuel pump for supplying liquid fuel to thecylinder combustion chamber, said pump including a regulating elementbiased to an initial position determining a minimum or pilot quantitydelivery by the pump.

and movable therefrom for regulating pump de-' livery between saidminimum quantity and a maximum quantity, conduit means for supplyinggaseous fuel to said auxiliary combustion chamber, said conduit meansincluding a supply control valve and a metering valve providing amovable valve element having an initial fuel metering position, saidvalve element being movable in one direction relative to its saidinitial position through a gaseous fuel metering range, and in theopposite direction relative to said initial position through anon-metering range, an engine driven governor operable through first andsecond control ranges, a governor actuated member operatively connectedto said metering valve element, an arm fixed on said member in aposition for operating engagement with said pump regulating element,said governor when operating in said first control range thereof,actuating said member to operate said metering valve element in saidnon-metering range thereof and to effect through engagement of said armwith said pump regulating element, movement of said regulating elementfor regulating pump delivery between said minimum and maximum quantitydelivery, and said governor when operating in said second control rangethereof, actuating said member to operate said metering valve element insaid gaseous fuel metering range thereof and to displace said arm fromengagement with said pump regulating element, with the regulatingelement then in said biased initial position thereof to determine saidpilot quantity delivery by the' pump, selectively conditionable controlmeans effective in one control condition for establishing closure ofsaid supply control valve during engine operation with the governoroperating in said first control range, and effective in a second controlcondition for establishing an open condition of said supply controlvalve during engine operation with the governor operating in said secondcontrol range, a stop element on said governor actuated member, and anabutment element positionable with selective conditioning of saidcontrol means, the abutment element in said second control condition ofthe control means, being positioned for engagement by said stop elementto restrain said governor actuated member against governor actuationthereof to engage said arm with said pump regulating element.

v exhaust ports, means providing a combustion space auxiliary to thecylinder combustion cham' her, a passageway interconnecting said chamberand space, a valve device in control of said passageway, an enginedriven variable delivery fuel pump for supplying liquid fuel to thecylinder combustion chamber, said pump including a regulating elementbiased to an initial position determining pump delivery of a minimum orpilot fuel quantity and movable therefrom for varying pump deliverybetween said minimum and a maximum fuel quantity, gaseous fuel supp-1ymeans for said combustion space, including a supply control valve and ametering valve providing a movable valve element having an initial fuelmetering position, said valve element being movable in one directionrelative to its said initial position through a gaseous fuel meteringrange, and in the opposite direction relative to said initial positionthrough a non-metering range, engine starting and running control meansselectively conditionable for effecting in one control conditionthereof, closure of said gaseous fuel supply control valve and closureof said valve device to close said passageway, said control meanseffecting in a second control condition thereof, opening of said supplycontrol valve and said valve device, an engine driven governor operablethrough first and second control ranges, a governor actuated memberoperatively connected to said metering valve element, and an arm on saidgovernor actuated member in a position for engagement with said pumpregulating element, said governor operating in said first control rangethereof during engine operation with said control means in said onecontrol condition thereof, and actuating said member to operate saidmetering valve element in its said non-metering range and to operatesaid arm in engagement with said pump regulating element to position theelement for regulating pump fuel delivery between said minimum andmaximum, and said governor operating in said second control rangethereof during engine operation with said controlmeans in said secondcontrol condition, and actuating said member to operate said meteringvalve element in its said metering range and to locate said arm out ofengagement with said pump regulating element, said element then being inits said biased initial position.

3. In a dual fuel internal combustion engine as defined by claim 2,characterized further by stop means operatively associated with saidgovernor actuated member, and abutment means effective in said secondcontrol condition of the control means and through engagement of saidstop means therewith, for restraining the governor actuated memberagainst governor actuation thereof to engage said arm with said pumpregulating element.

STUART D. KLINGER.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,833,265 Schmidt Nov. 24, 1931 1,858,324: Heidelberg May 17,1932 2,400,219 Barnaby et a1 May 14, 1946 2,400,247 Miller et al. May14, 1946 2,562,511 Soho-Walter July 31, 1951 OTHER REFERENCES The OilEngine of December 1941, pp. 199-201.

